TY - GEN A1 - Medina Méndez, Juan Ali A1 - Dorneanu, Bogdan A1 - Arellano-García, Harvey T1 - Homogeneous modeling for laminar flows in structured catalysts: CO2 methanation T2 - Book of Abstracts zur Jahrestagung der DECHEMA/VDI-Fachgruppe Fluidverfahrenstechnik, 04. – 06. März 2024 Y1 - 2024 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2024_AbstractDechemaFluidverfahrenstechnik_Catalysts.pdf PB - Ruhr Universität CY - Bochum ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Dorneanu, Bogdan A1 - Arellano-García, Harvey T1 - Homogeneous modeling for laminar flows in structured catalysts: CO2 methanation Y1 - 2024 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2024_Poster_DECHEMA2024_Fluidverfahrenstechnik.pdf CY - Bochum ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Dorneanu, Bogdan A1 - Schmidt, Heiko A1 - Arellano-García, Harvey T1 - Revisiting homogeneous modeling with volume averaging theory: structured catalysts for steam reforming and CO2 methanation T2 - Journal of Physics: Conference Series N2 - Progress in the modeling of structured catalysts is crucial for enhancing efficiency and scalability in industrial applications. Extensive research has investigated reactive flows over catalyst surfaces, covering chemical kinetics analysis and (direct) numerical simulations of the complete fluid flow in fixed-bed or structured catalysts. Nonetheless, this comes at a high computational cost. This study focuses on the homogeneous modeling of structured catalysts utilizing volume-averaging theory (VAT) as a more efficient method for representing the behaviour of such systems. We discuss modeling strategies for both 1-D and 3-D simulations. For steady 1-D flow simulations, we assess the influence of simplified gas chemical kinetics versus detailed surface chemistry, comparing with experimental data from the literature for a CO2 methanation processes. We also simulate 3-D flows of a steam reforming process, previously studied in the literature, using models which rely on different assumptions regarding the nature of the porous catalyst. Our findings reveal significant discrepancies based on different modeling assumptions, underscoring the necessity for accurate modeling of permeability and diffusivity tensors in homogeneous models. Y1 - 2024 U6 - https://doi.org/10.1088/1742-6596/2899/1/012004 SN - 1742-6596 VL - 2899/2024 ER - TY - GEN A1 - Medina Méndez, Juan Alí A1 - Parra Lafuente, Adrián A1 - Schmidt, Heiko T1 - A volume-averaging and stochastic turbulence modeling framework for homogeneous roughness-induced drag in turbulent flows T2 - Special Issue: 94th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM) N2 - The goal of this work is the formulation of a model for the parameterization of homogeneous roughness-induced drag in turbulent flow simulations. We characterize rough surfaces using their surface-area moments of roughness-peaks. Additionally, we consider a probabilistic self-similar power law distribution for the roughness heights, in such a way that an assumed set of discrete roughness elements can behave as a probabilistic fractal set. Upon these assumptions, the surface characterization is complete and yields wall-normal profiles of porosity, average roughness element diameter, and equivalent pore diameter of the roughness affected porous flow. The profiles are supplied to a (pore-based) Reynolds number and porosity-based drag parameterization for staggered cylinder arrays available in the literature, as well as a one-dimensional map-based turbulence model, the one-dimensional turbulence (ODT) model. The purpose of the latter is a way to provide the missing effects of the equivalent dispersion tensor in the porous flow close to the rough surface, as well as that of the nonlinear turbulent transport away from the wall. Simulations are then carried out in order to evaluate the effects of two different rough surfaces on a turbulent channel flow, comparing results with existing direct numerical simulation (DNS) data. Overall, reasonable agreement is obtained, which suggests that, by using the proposed model, it is possible to model the effects of rough surfaces on wall-bounded turbulent flows, without the explicit need of the full topological representation of the surface on the numerical domain. To that extent, one clear flow control application for the suggested approach would be that of drag-based surface optimization. Y1 - 2024 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/pamm.202400136 U6 - https://doi.org/10.1002/pamm.202400136 SN - 1617-7061 VL - 24 IS - 3 SP - 1 EP - 13 PB - Wiley ER - TY - GEN A1 - Medina Méndez, Juan Alí A1 - Dorneanu, Bogdan A1 - Schmidt, Heiko A1 - Arellano-García, Harvey T1 - Revisiting homogeneous modeling with volume averaging theory: structured catalysts for steam reforming and CO2 methanation T2 - Book of Abstracts XXVI Fluid Mechanics Conference (FMC 2024), Warsaw, Poland, September 10-13, 2024 Y1 - 2024 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2024_AbstractFMC26_Catalysts.pdf PB - University of Technology CY - Warsaw ER - TY - GEN A1 - Naik Burye, Nishidh Shailesh A1 - Medina Méndez, Juan Alí A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Revisiting near-wall modeling of fully developed turbulent flow in concentric annuli T2 - Jahresbericht 2024 zum 24. DGLR-Fachsymposium der STAB 13.-14. November 2024, Regensburg Y1 - 2024 UR - http://bfm.rcbe.de/files/2024/11/2024_STAB-Jahresbericht.pdf SP - 174 EP - 175 PB - Deutsche Strömungsmechanische Arbeitsgemeinschaft, STAB CY - Regensburg ER - TY - GEN A1 - Joshi, Abhishek A1 - Medina Mendez, Juan Ali A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Simulating homogenous isotropic turbulence with deterministic and stochastic forcings using a one-dimensional turbulence model N2 - To understand the intermittency present in scalar fields we need to address the expense of current start-of-art DNS to probe the higher-order structure functions. These higher order moments become increasingly sensitive to increasing Reλ and much more prone to extreme events. Here, in this work, we investigate using a Reduced order model(ODT) to simulate Homogenous Isotropic turbulence as an initial step towards that goal by employing a linear forcing [1] proposed by Lundgren that is proportional to local and instantaneous velocity. Y1 - 2024 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Joshi_2024_MFM_Poster.pdf ER - TY - GEN A1 - Marinković, Pavle A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko A1 - Klein, Marten T1 - Ongoing development of a hybrid reduced order stochastic/LES solver for turbulent flows Y1 - 2024 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Marinkovic_2024_EIZ_poster.pdf CY - Cottbus ER - TY - GEN A1 - Klein, Marten A1 - Schöps, Mark Simon A1 - Medina Méndez, Juan Alí A1 - Schmidt, Heiko T1 - Numerical simulation and analysis of transient Ekman boundary layers using a stochastic turbulence model T2 - EGU General Assembly 2023 KW - stochastic modeling KW - one-dimensional turbulence KW - turbulent Ekman flow KW - transient boundary layer Y1 - 2023 UR - https://meetingorganizer.copernicus.org/EGU23/EGU23-9116.html U6 - https://doi.org/10.5194/egusphere-egu23-9116 PB - EGU - European Geophysical Union CY - Vienna, Austria ER - TY - GEN A1 - Medina Méndez, Juan Alí A1 - Sharma, Sparsh A1 - Schmidt, Heiko A1 - Klein, Marten T1 - Towards the use of a reduced order and stochastic turbulence model for assessment of far-field sound radiation: low Mach number jet flows T2 - Book of Abstracts of the 93rd Annual Meeting of the International Association of Applied Mathematics and Mechanics KW - turbulent noise sources KW - reduced-order modeling KW - one-dimensional turbulence KW - turbulent jet KW - stochastic modeling and simulation Y1 - 2023 UR - https://jahrestagung.gamm-ev.de/wp-content/uploads/2023/05/20230517_BookofAbstracts_final_red.pdf SP - 413 EP - 414 PB - GAMM e.V. CY - Dresden ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Sharma, Sparsh A1 - Schmidt, Heiko A1 - Klein, Marten T1 - Toward the use of a reduced-order and stochastic turbulence model for assessment of far-field sound radiation: Low Mach number jet flows T2 - Proceedings in Applied Mathematics and Mechanics Y1 - 2023 U6 - https://doi.org/10.1002/pamm.202300186 SN - 1617-7061 VL - 23 IS - 3 ER - TY - GEN A1 - Klein, Marten A1 - Medina Méndez, Juan Alí A1 - Schöps, Mark Simon A1 - Schmidt, Heiko A1 - Glawe, Christoph T1 - Towards physics-based nowcasting of the instantaneous wind velocity profile using a stochastic modeling approach T2 - STAB Jahresbericht 2024 zum 24. DGLR-Fachsymposium der STAB, 13. - 14. November 2024, Regensburg N2 - The primary objective of this contribution is to provide an overview of the regime-spanning forward modeling capabilities offered by the stochastic one-dimensional turbulence model. The focus is on the applicability of the model and its validation for neutral and stable atmospheric boundary layer flows as a prerequisite for future applications to challenging atmospheric conditions. KW - atmospheric boundary layer KW - stochastic modeling KW - one-dimensional turbulence KW - wind energy KW - wind shear and veer Y1 - 2024 UR - https://bfm.rcbe.de/files/2024/11/2024_STAB-Jahresbericht.pdf SP - 162 EP - 163 PB - Deutsche Strömungsmechanische Arbeitsgemeinschaft, STAB CY - Regensburg [et al.] ER - TY - GEN A1 - Klein, Marten A1 - Medina Méndez, Juan Alí A1 - Schmidt, Heiko T1 - Resolving the electrostatic boundary layer in a turbulent electrohydrodynamic flow with a map-based stochastic modeling approach T2 - 1st European Fluid Dynamics Conference - Daily Scientific Program N2 - Electrohydrodynamically (EHD) enhanced wall-bounded turbulent flows are encountered in various technical applications ranging from air-cleaning devices (like precipitators) to electrolyte flows (like redox flow batteries). The multi-physical processes governing the flow properties, however, are not yet very well understood. This is due the inaccessibility to and limitations of measurement equipment and numerical resolution requirements imposed by the electrostatic charge boundary layer that interacts on different time scales with the turbulent boundary layer. Recent advances in measurement techniques allow to resolve the exponential electrostatic charge boundary layer in a charged particle-ladden, weakly turbulent gas flow [1], which is qualitatively compatible with direct numerical simulation (DNS) results for a weakly turbulent flow of an electrolyte [2] at low Reynolds (Re) number. The challenge that remains is the extrapolation to highly turbulent flow conditions. Charged particles are heavy compared with fluid molecules and can be treated as a high Schmidt (Sc) number scalar, which is a burden for DNS. In this contribution, it is demonstrated that this burden can be overcome for the transient boundary layer evolution by utilizing a radically reduced, map-based stochastic one-dimensional turbulence (ODT) model. The model predicts a significant enhancement of the skin friction drag due to turbulence-induced screening layer depletion [3], as summarized in Fig. 1. In the talk, features of the instantaneous and mean velocity and electrostatic boundary layer will be presented. The plausibility of the model prediction is evaluated on a physical basis, encompassing details of the model formulation and the emerging hydrodynamic and electrokinetic properties of the boundary layer. References [1] W. Xu, S. Jantaˇc, T. Matsuyama, and H. Grosshans. arXiv:2306.06970, 2023. (Accepted for publication by Exp. Fluids.) [2] R. Ostilla-M´onico, and A. A. Lee. Faraday Discuss., 199:159–173, 2017. [3] M. Klein, J. A. Medina M´endez, and H. Schmidt. Tech. Mech., 43:111–127, 2023. KW - EHD turbulence KW - electric double layer KW - boundary layer KW - Schmidt number effects KW - one-dimensional turbulence KW - stochastic modeling KW - skin friction drag Y1 - 2024 UR - https://www.conftool.org/efdc1/index.php?page=browseSessions&presentations=show&search=822+klein UR - https://www.aia.rwth-aachen.de/fileadmin/user_upload/Daily_Scientific_Program.pdf CY - Aachen ER - TY - GEN A1 - Klein, Marten A1 - Starick, Tommy A1 - Zenker, Christian A1 - Medina Méndez, Juan Alí A1 - Schmidt, Heiko T1 - Reduced order stochastic modeling of turbulent mixing based on conservative baker’s maps T2 - Proceedings of the 14th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements (ETMM-14) N2 - The detailed numerical representation of turbulent mixing processes is a standing challenge for non-premixed chemically reacting flows. The full range of relevant flow scales needs to be captured and it is also necessary to distinguish turbulent advective from molecular diffusive processes in order to represent Reynolds and Schmidt number effects. These requirements are addressed here by utilizing two different map-based stochastic turbulence modeling strategies. The one-dimensional turbulence (ODT) model utilizes event-based turbulence modeling, whereas the hierarchical parcel-swapping (HiPS) model is a fully event-based mixing model. ODT provides full-scale resolution at affordable costs by dimensional model reduction based on the boundary-layer approximation to shear flow. HiPS is far less costly than ODT but currently limited to locally homogeneous isotropic turbulence. The physics-compatible modeling capabilities with respect to phase-space representation of turbulent mixing are demonstrated for two canonical cases using standalone model formulations. KW - turbulent mixing KW - one-dimensional turbulence (ODT) KW - hierarchical parcel swapping (HiPS) KW - stochastic turbulence modeling KW - round jet KW - passive scalar Y1 - 2023 UR - https://etmm.ercoftac.org/etmm/program/conference-program/ UR - https://drive.google.com/file/d/1q2BDOO5bXfqq0Y4z4HCGndiFI033bPyg/view?usp=drive_link SP - 613 EP - 618 PB - ERCOFTAC CY - Barcelona, Spain ER -